View Compilation Error

0_0_9016509_8705.c:2:20: algorithm: No such file or directory
0_0_9016509_8705.c:3: error: syntax error before "namespace"
0_0_9016509_8705.c:9: error: syntax error before "x"
0_0_9016509_8705.c: In function `cmp':
0_0_9016509_8705.c:10: error: `x' undeclared (first use in this function)
0_0_9016509_8705.c:10: error: (Each undeclared identifier is reported only once
0_0_9016509_8705.c:10: error: for each function it appears in.)
0_0_9016509_8705.c:10: error: `y' undeclared (first use in this function)
0_0_9016509_8705.c: In function `main':
0_0_9016509_8705.c:14: error: `stone' undeclared (first use in this function)
0_0_9016509_8705.c:14: error: syntax error before "st"
0_0_9016509_8705.c:20: error: `st' undeclared (first use in this function)